The purpose of this study was to determine whether (or not) 5-HTTLPR genotypes moderate known associations between attachment style and adolescent anxiety and alcohol use outcomes.
However, the influence of the 5-HTTLPR genotype on hippocampal neuronal development and neurochemistry, which is relevant to anxiety behavior, has not been investigated.
Negative affect such as depression and anxiety has been reported to be associated with morbidity and mortality, and polymorphisms of the serotonin transporter (5HTT) gene may be associated with such affect disorders.
Due to its central role in the fine-tuning serotonergic neurotransmission, a regulatory variant of the 5-HTT, which is associated with anxiety related traits, is not only a key player in the neurobiological mechanism of gene x environment interaction in the etiology of depression, but also contributes to the risk to develop alcohol dependence with antisocial behavior and suicidality.
In turn, corticolimbic circuit function predicts individual differences in an experimental index of temperamental anxiety and, thus, might reflect a predictive biological marker of increased risk for mood disorders associated with the 5-HTTLPR.
A commonly occurring polymorphic variant of the human 5-hydroxytryptamine (5-HT) transporter (5-HTT) gene that increases 5-HTT expression has been associated with reduced anxiety levels in human volunteer and patient populations.
The paper focuses on such candidate gene polymorphisms that alter alcoholism-related intermediate phenotypes including: dopaminergic system polymorphic variants (DRD2 -141C Ins/Del in promoter region, exon 8 and DRD2 TaqI A and DAT 40bp VNTR genes polymorphisms) that cause predisposition to severe alcoholism (haplotype Ins/G/A2); COMT Val158Met gene polymorphism related to differences in executive cognitive function and 5-HTT gene promoter polymorphism, which alters stress response and affects anxiety and dysphoria.
The serotonin transporter gene (SLC6A4) is a strong autism candidate gene because of its association with anxiety, aggression and attention, and the effectiveness of selective serotonin reuptake inhibitors (SSRIs) in treating certain behavioral symptoms.
The s allele variant of the serotonin transporter gene (5-HTT) has recently been observed to moderate the relationship of stress to depression and anxiety.
Short allele (S) of the 5-HTTLPR polymorphism in the promoter region has been shown to be associated with impulsivity, aggressive behavior, anxiety and neuroticism.
These effects may underlie the vulnerability to mood and anxiety disorders potentially triggered by socially salient, emotional cues in individuals with the S allele of 5-HTTLPR.
For that reason we hypothesized that homozygous 5-HT transporter knockout rat (SERT(-/-)) models, especially female, are valuable and reliable animal models for humans with an increased vulnerability for anxiety- and depression-related disorders.
The efficacy of serotonin reuptake inhibitors in depression and anxiety disorders suggests the gene coding for the serotonin transporter (5-HTT), SLC6A4, as a candidate of importance for these conditions.
The promoter region of the serotonin transporter gene (SLC6A4) shows a 22-bp tandem repeat polymorphism, indicated as polymorphism C, that has been associated to depression, obsessive-compulsive disorder, memory impairment, and anxiety.
A polymorphism in the human serotonin transporter (5-HTT) gene is implicated in susceptibility to anxiety and depression and in enhanced emotion-induced activation in the amygdala.
These findings suggest that within this restricted population increased symptoms of depression, anxiety, and memory are associated with the 5-HTTLPR polymorphism among both males and females.
Individuals with the LL genotype of 5-HTTLPR who were exposed to high family adversity displayed significantly higher rates of depressive or anxiety disorders and had more depressive symptoms than those without either condition.
The human serotonin (5-hydroxytryptamine, 5-HT) transporter (hSERT, SLC6A4) figures prominently in the etiology and treatment of many prevalent neurobehavioral disorders including anxiety, alcoholism, depression, autism, and obsessive-compulsive disorder (OCD).
After effects of treatments were removed, 5-HTTLPR low-function allele carriers showed smaller treatment reductions in binge eating (p < .01) and in anxiety and depression (p < .05), whereas low-function -1438G/A G carriers showed smaller reductions in binge eating (p < .01) and impulsivity (p < .05).
In the SardiNIA sample, we found no significant association of the 5-HTTLPR genotypes with Neuroticism or its facets (Anxiety, Angry-Hostility, Depression, Self-Consciousness, Impulsiveness, and Vulnerability).